Polybutadiene is a polymer compound which may be obtained by polymerization of a butadiene monomer generally represented by 1,3-butadiene, wherein the polybutadiene is being used as a material of various products due to excellent abrasion resistance and flexibility as well as lightness. About 70% of the polybutadiene is used for manufacturing tires in which the abrasion resistance is important, and about 25% of the polybutadiene is used as an additive for improving mechanical strength of plastic such as polystyrene or acrylonitrile butadiene styrene (ABS). In addition, polybutadiene is also used as a coating material for electronic assemblies due to high electrical resistance, and its use may be considered to be infinite, for example, it is used for the manufacture of golf balls (core portion) or numerous elastic materials.
An apparatus or method for preparing the polybutadiene has long been recognized as a well-known technique. However, in a polymerization process for preparing polybutadiene, a heat exchange efficiency may be reduced due to a phenomenon, in which a portion of a polymer is incorporated into a condenser configured to cool a gas mixture, which is generated by polymerization heat and discharged to the top of a reactor, and deposited inside the condenser and a gas discharge pipe located between the polymerization reactor and the condenser, that is, a plugging phenomenon, and it is more likely that the plugging phenomenon may be accelerated as a flow rate of the discharged gas mixture increases.
Also, a Ziegler-Natta metal catalyst is typically used for the polymerization of polybutadiene, wherein, since activity of the catalyst is sensitively reduced due to moisture, suspension polymerization mainly using water as a heat transfer medium or emulsion polymerization mainly using water as an emulsion matrix may not be an effective synthesis method for the polymerization of polybutadiene. Thus, in order to uniformly form a polymer structure, it is required to secure a high conversion rate above a certain level in a first polymerization step, and, for this purpose, since polymerization heat generated in a first polymerization reactor is inevitably and significantly increased, the plugging phenomenon is further accelerated.
Polybutadiene is usually prepared by continuous polymerization using two or more reactors, wherein, when the polybutadiene is prepared by such a method, residence time of a reaction raw material in the polymerization reactor is increased and the conversion rate is also increased, but, since the residence time is inversely proportional to an amount of the raw material added to the reactor, there is a need to properly configure an overall environment such as the number and arrangement of the polymerization reactors.
Various apparatuses and methods for preparing polybutadiene are known, for example, Korean Patent Application Laid-open Publication No. 10-2015-0028615 (method and apparatus for preparing butadiene rubber with reduced plugging) discloses that a plugging phenomenon is reduced by continuous polymerization using two polymerization reactors, and Korean Patent Publication No. 10-2013-0003125 (method of preparing 1,3-butadiene using parallel reactor) discloses that two polymerization reactors are configured in parallel so that a catalyst varies depending on raw materials supplied differently, and diverse research for further improving these apparatuses and methods has been conducted.